Hey there! I'm Imran, I am working with DevOps tools and technologies and learning them also. I believe in learning in public, sharing my learnings and knowledge with everyone in the community and learn from everyone in the community. And I am writing my first blog about a topic in Computer Networking that I learned in Computer Networking course by Kunal Kushwaha and other sources.

OSI Model

• OSI stands for Open Systems Interconnection Model.
• OSI consists of seven layers and each layer performs a particular network function.

Layers of OSI Model

1. Application Layer

• It is the topmost layer in OSI model.
• It is implemented in Software.
• This layer provides services to the user.
• This layer includes all high level protocols like Telnet , DNS , HTTP , FTP , SMTP , etc.

2. Presentation Layer

It is responsible for :

• Data encryption/decryption
• Character/string conversion
• Data compression
• Graphic handling
• Translation

The presentation layer mainly translates data between the application layer and the network format

3. Session Layer

It is used to :

• Establish sessions
• Manage sessions
• Terminate the sessions

It controls the connections/sessions between computers. It establishes, manages, and terminates the connections/sessions between the local and remote application

4. Transport Layer

• It is responsible for error-free and end-to-end delivery of data.
• The protocols defined here are TCP ( Transmission Control Protocol ) and UDP ( User Datagram Protocol ).

Transport Layer provides transparent transfer of data between end users, providing reliable data transfer services to the upper layers.

5. network layer

• It is responsible for moving the data packets from source to the destination.
• It works for the transmission of received data segments from one computer to another that is located in a different network
• Router lives over here.
• It assigns sender's and receiver's IP address to every segment and it forms and IP packet. This is known as logical addressing.

6. Data Link Layer

• The data link layer is responsible for error free transfer of data frames.
• The main function of this layer is to make sure data transfer is error-free from one node to another, over the physical layer.
• The packet received from the Network layer is further divided into frames depending on the frame size of NIC(Network Interface Card).

7. Physical Layer

• It is the lowest layer of the OSI model.
• it provide physical medium through which bits are transmitted.
• The physical layer contains information in the form of bits.
• It is responsible for the actual physical connection between the devices.

So this is the article/blog. I hope you find it informative and helpful. If you like it please follow , like and share. I will keep writing informative blogs related to DevOps. Pleae give your feedback in the comments. Thank You !!!!